Worn out cat ?

[sigma]

I have a Y reg Renault Clio. When started from cold there is a strong smell of eggs/sulphur which I assume is coming from the cat. Is this an indication that the cat is on its way out.
Please, no comments about pussy cats.

[jake-the-peg]

Sounds more likely to be the battery to me - check it carefully for cracks.

No sulphur in a cat - plenty of sulphuric acid in a battery!

Be careful if it is cracked or leaking acid burns aren't nice

[mccfluff]

i'll get me coat

[ChuckFickens]

Could be either the battery being overcharged or starting to run dry, or it could be the CAT.

Although there is no sulphur in the cat there is sulphur in petrol which if it's not fully burned gets stored in the cat and can be released as hydrogen sulphide (stinks of eggs!) under certain running conditions.

try an different brand of fuel first, as some have a lot higher sulphur content than others.

[jake-the-peg]

It's not a lot though Chuck - I have a 64 MGB no cat there and I've never smelt sulphur

[AlBags]

It's the CAT ... and it's normal.
Warm up cycle, the ECU controls the fuel going to the injectors to get the cat up to working temperature quickly. This happens in first 2 minutes of running from cold start.

[sigma]

If it's the CAT, why has it only just become noticeable.

[AlBags]

It's always done it ... Sometimes, yoiu will get excess smell when it's burning off extra fuel.
Ignore it.
Some Volvos have incredibly smelly cats for some reason.